Alcoholism is a major public health problem that cost the nation billions of dollars annually. Ethanol modifies the function of receptors and G proteins that coordinately regulate intracellular cAMP. Using cultured clonal neural cell lines, we have developed a model system to help define the cellular and molecular event that underlie alcohol intoxication, tolerance, and physical dependence. We propose to evaluate how modulation of delta-opioid receptors by acute and chronic ethanol treatment influences receptor-mediated inhibition of cAMP accumulation and stimulation of low KM GTPase activity. Using whole cell and patch clamp techniques we will correlate biochemical effects of ethanol with physiological action on opioid receptor-Go-mediated inhibition of voltage-dependent calcium channels and receptor-G1- medicated stimulation of potassium channels. Using radioligand binding immunoblotting, and Northern analysis we will explore the molecular mechanism whereby adaptation to ethanol leads to changes in delta-opioid receptors, Gs, Gi and Go and their respective mRNA's. We will examine the potential roles of ethanol induced histone hyperacetylation, changes in cAMP, and changes in cell cycle in provoking cellular adaptation. By characterizing differences in the acute and adaptive responses of genetically related clonal neural cell lines, we may help explain the intrinsically different capacity of diverse brain regions and individuals to respond and adapt to ethanol. Our proposed studies of dividing neural cells will advance the understanding of how maternal alcoholism may lead to the neurodevelopmental abnormalities of the fetal alcohol syndrome. Our biochemical and physiological studies of differentiated neural cells may advance the search for biological markers in patients at risk for alcoholism and more rational therapy for those already affected.